CHICAGO (CNN) -- Gun violence has inextricably joined Michelle and Barack Obama with a family from their Chicago neighborhood, and the president will give them a place of prominence during Tuesday night's State of the Union address.

Honor student Hadiya Pendleton had performed as a drum majorette at an event during President Obama's second inauguration in Washington and was gunned down days later.

The presence of her father, Nathaniel, and mother, Cleopatra, sitting by the first lady's side, will be no coincidence and part of the president's message to the nation.

In his address, Obama will renew his support for the gun proposals he's already endorsed, including a ban on military-style assault weapons and bolstering background checks, officials have said.

Pendleton's alleged killers -- both of them gang members -- will appear in court for the first time Tuesday morning in Chicago, police there said. One of them confessed Monday, saying he mistook Pendleton and her friends for someone else.

The honor student was openly opposed to gang membership, taking to Twitter to discourage her followers from joining.

She was 15 when she died after being shot in the back at a playground in late January, in Chicago's Hyde Park neighborhood, not far from the Obama family home.

The first lady attended her funeral.

The president will visit Chicago Friday to talk about gun violence in the wake of 500 shooting deaths in his home town in 2012. Pendleton was the 42nd victim shot dead in the city this year.

The killing has prompted a ranking Chicago police official to call for stricter penalties against gun offenses.

Michael Ward, 18, and Kenneth Williams, 20, were each charged with one count of murder and two counts of attempted murder, Police Superintendent Garry McCarthy said.

Ward said he shot Pendleton, when he and Williams were out to get revenge on rival gang members, according to police.

The men had fired upon Williams in July, wounding him in the arm, McCarthy said. When police arrested them, Williams refused to press charges.

Instead he apparently decided to take matters into his own hands and, at best, made a serious error.

"The offenders had it all wrong," McCarthy said. "They thought the group they shot into included members of a rival gang."

Shatira Wilks, one of Hadiya's cousins, said Hadiya was hanging out with a volleyball team -- a group of girls and one boy -- when she was killed.

Williams allegedly drove getaway and waited in a car for Ward, who wielded the gun, McCarthy said.

Police initially received no solid tips on the shooter's identity, but they did get a description of the car, which they were able to link to a traffic stop days before the killing.

That, along with information from parolees, led them to the two men.

Ward surrendered on Saturday night without a struggle, McCarthy said, but Williams tried to escape.

Wilks said the family was elated that the suspects were in jail.

"However there is no level of comfort -- not long-term comfort -- and we are still miserable," she said.

The shooting should not have happened, McCarthy said, openly frustrated with Illinois' gun laws.

Ward was already on parole for a previous gun violation -- unlawful use of a firearm -- when he shot Pendleton, McCarthy said. He thinks he should have been behind bars and not walking around free.

"Michael Ward would not have been on the streets of New York City to commit this act, if it had happened there," McCarthy said.

"This is not about gun control, he said. This is about the criminal justice system being designed to prevent gun violence."

The police superintendent called for mandatory minimum sentences for gun crimes. What he wants most are controls surrounding the "loss, theft or transfer of firearms."

President Obama hand-wrote a note to Pendleton's parents, when she died. It was printed on the funeral program and included a promise to take action:

"We know that no words from us can soothe the pain, but rest assured that we are praying for you, and that we will continue to work as hard as we can to end this senseless violence. God Bless, Barack Obama."